It is known to provide a balloon comprising an inflatable envelope which is inflated with a gas such as air or helium, place a light source in the balloon and tether the balloon to the ground using an elongate element keeping the balloon at a certain height above the ground. Such balloons are used either for decoration, for carrying advertisements where the envelope or fabric of the balloon carries such an advertisement or for the provision of a diffused light source which may for example be needed for filming, photography, civil works, construction, or for use by emergency services.
It is known to provide such inflatable balloons with a deformation sensing means such that if the balloon loses pressure and deforms, the power to the light bulb is cut for safety reasons. However, there are a number of problems with such balloons.
Inflatable balloon envelopes tend to deform quite readily when subject to relatively strong air currents because of the relatively low pressure setting and even the smallest holes in the envelope may cause the safety circuit to cut power to the bulb. In more adverse conditions, illuminated balloons switch off more often and provide unsatisfactory lighting. The prior art deflection systems are typically mechanical systems such as the filar elements of U.S. Pat. No. 5,782,668 and are unreliable, over-sensitive and difficult to adjust.
The current method of supporting large inflatable lighting balloons is to rig the balloons onto scaffolding which is then supported by a cherry picker, this arrangement also being referred to below as a conventional lighting tower.
This method is awkward to use and is not well suited to many applications, particularly when reliable and quick anchoring of the balloons is required.
A second problem with existing conventional lighting towers is that a very heavy base is required. A conventional mines lighting tower may weigh up to 5000 Kg.
There is a third problem with existing inflatable balloon systems and that is their slow inflation rate and noisy operation which is a particular problem when filming.
The aim of the present invention is to ameliorate or at least alleviate the above mentioned disadvantages of the prior art.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application.